When population booms in poor nations

Posted by Dave on March 17, 2010 | 4 Comments

As I’ve mentioned in previous posts, population isn’t growing evenly across the world. While some areas are growing quickly, other places are stagnating. In nearly every case, population growth is slowest in rich countries and faster in poor countries. These two maps from the UN Population Division perhaps show the trend most dramatically:

As you can see, fertility (average number of children born per woman) has declined dramatically, but there are still many regions with fertility above 2.1 — the rate that most economists feel is necessary to maintain a steady population.

All this has occurred while mortality has declined nearly everywhere, which is why some nations are experiencing dramatic population growth. Which countries will grow the fastest in the next 40 years — and what will that mean for living conditions in those countries?

Nikos Alexandratos took a look at the prospects for the 19 fastest-growing countries in the world (in population). For the most part, these are some of the poorest places on the planet: Afghanistan, Angola, Benin, Burkina Faso, Burundi, Chad, Congo, Democratic Republic of Congo, Eritria, Ethiopia, Iraq, Liberia, Madagascar, Mali, Mauritania, Niger, Somalia, Uganda, and Yemen. The one outlier might be Iraq.

Will these countries be able to support the huge population gains they are expected to experience in the next 40 years? Alexandratos says it’s difficult to assess. The key question in 12 of the cases where the countries don’t have the resources to pay to import food: Is there enough arable land to provide food for the expected population boom? These countries are expected to triple or quadruple in population. Afghanistan, for example, is projected to grow from 21 million in 2000 to 69 million in 2050. The Democratic Republic of Congo could grow from 48 million to 151 million.

Alexandratos compared these population estimates to the area of land available for cultivation. He tried to account for technological gains that could increase productivity. As you might expect if you’ve been reading this month’s posts, the prognosis is different in each country. Chad is only currently using about 10 percent of the land that could be used for agriculture, so even with a projected tripling of population, it’s probably still possible for the country to produce enough food. But Burundi currently farms about 80 percent of its arable land. A tripling of its population could be devastating—and Alexandratos doesn’t even take climate change into account. Africa, where much of the population increase over the next 40 years is expected to occur, is also the region that may be hardest-hit by climate change.

I started this month speculating that population growth might be one of the the prime influences on global warming. It’s looking more and more like population is growing in places that don’t impact the climate so much—but places that will be disproportionately affected by climate change. But as these regions begin to feel the effects of climate change, what does seem like a distinct possibility is migration to wealthier regions; which could in turn cause more global warming.

Nikos Alexandratos (2005). Countries with Rapid Population Growth and Resource Constraints: Issues of Food, Agriculture, and Development Population and Development Review, 31 (2), 237-258

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